Understood. The offer is still there should you change your mind.

Knowing you have a cat bypass is good info -- we can rule out clogged cat.

I'm going to PM you my mobile number. I will be working on my car later tonight and the rest of the weekend. Feel free to call me. I am hoping we're close to getting this licked!

Hey, congrats on the adoption! Big news! One minute the kids are just little things and the next minute you're teaching them to drive the 911. :eek:

Ok, I have to ask as I haven't noticed it mentioned.
Does adjusting the idle air bypass screw on the throttle body out have any effect on the idle when the car is warm and stumbling?

Yes, if I open up the idle screw, the idle moves higher and I have a little longer before I have to hold the throttle manually. When I had the throttle body out, I cleaned it very well and air passage through the idle bypass part is good.

Video will be up in half an hour or so. Going to go ahead and see about WUR pressure impact while it uploads.

Engine off, FP on, WUR quite warm from the last test. Hooked up my hand vacuum pump to the WUR vacuum input.
One squeeze, which read as -40 kpa on the pump, was about 1 Bar of increased fuel pressure. The pressure increases dropped off right away when pressure was released.

15 minutes remaining on the video.

Apparently "processing" is another progress bar after uploading.

http://youtu.be/aEkrW6WOfD0

The outside tick marks on the gauge are 1 Bar increments. If you pull it up in youtube, you can see the dial better.

<iframe width="560" height="315" src="https://www.youtube.com/embed/aEkrW6WOfD0" frameborder="0" allowfullscreen></iframe>

First observation/question: Why is the CP going up as the revs are going up around the 4:55 - 5:05 minute time frame? Every time the engine runs up to about 3-4k when you open the throttle the CP goes to a healthy 3 bar only to drop right back to 2 bar when you let off the throttle.

I see at the beginning the CP drops to 0.7 bar or less during cranking. My guess: that makes the mixture way too rich to start.

Then around 3:30 minutes after enough warming of the WUR the CP only drops to 1.1 bar during cranking and the engine is eventually starting.

At around 5:04 after you rev the engine it appears the AAR closes and the engine settles into a high idle. At 5:08 you seem to turn the idle bypass almost all the way shut so the engine dies. Then you open the throttle but at that point it's too late.

Maybe open that idle bypass up just a little bit and see if smaller adjustments get you where you need to be for a more stable idle.

Some quick pics of AAR as it warms from very cold (Freezer for 30 minutes) to quite warm (haird dryer for 5 minutes).

Going to analyze Ingo's response in a sec.

It doesn't look like much change.

http://forums.pelicanparts.com/uploa...1436574814.jpg

I thought that was correct - when I rev, I get a higher vacuum in the airbox. Thus the surge in vacuum to the WUR and the increase in fuel pressure.
I could be totally wrong, but that was how I interpreted. Does high control pressure mean less fuel to the cylinders?

See pictures above for the range of movement I'm getting on the AAR. Note that that started from the freezer. Normally it moves from about the middle of that range.

At 5:08 I only turned about 1 turn (it was 4+ turns out already). So the idle is still fairly open at that point.

Yes, the higher the control pressure the more force onto the piston in the mixture control body pushing it lower -> less fuel. The lever pushes the piston up (more fuel) and the control pressure holds against that.

Your AAR seems to be doing its job.

Here is what I would try: Go back and back the idle bypass out so the engine keeps running at or above idle speed after you get it started. With that let it fully warm up (AAR in its final nearly closed position) at the elevated idle.

Then try to adjust the mixture (the screw that acts onto the piston. Find the points where the mixture gets too rich and too lean (engine starts to miss) and set it into the center of the two.

Then, carefully start closing the idle bypass to see if you can get the idle speed closer to specifications. I don't think you are too far away from a running engine.

Ingo

Bingo, that is why I asked about the idle bypass adjustment.
As you make any mixture adjustments you need to adjust the idle air in concert with it.
Make small richness adjustment, wait a minute or two for it to work its way through and then adjust idle. Might want to keep it in the 1200 rpm range to get it really close when at full operating temp and then fine tune the idle.
As you lean the mixture (everything points to being rich) you will need to adjust the idle air.

Fine tuning CIS is not like tuning a carb, it takes a little while for the adjustments to have an effect. It isn't quick!

I will give that a whirl in the morning. I'll have a friend on hand to help. The challenge is that, currently, it continues to want more and more air as it warms up.

We'll get it!

It will want more air due to being rich.
I remember fine tuning my CIS to get to the right mixture took a lot of time going back and forth adjusting the mixture and idle air screw.
Do you have a way to test the CO while you are adjusting the mixture?
My car ran great at a CO of 3.5.

I do not have a way to test the CO. I recall seeing a plug-type-thing on the cat bypass the last time I did valves. But there was nothing connected there.

That plug-type thing is probably the port for an O2 sensor. Without the wide-band I think your best bet is to slowly and incrementally get to a good setting for mixture and idle screw position.

I think once you do small adjustments tomorrow you'll get to an almost nice running engine before you take off for vacation. Then enjoy you vacation and meanwhile take the offer for the wide-band loaner. When you get back that'll allow you to make it perfect. And eventually you'll write a tutorial on how to troubleshoot and fine-tune CIS.... :D

Guys,

I spent some time on the phone tonight with OsoMoore. We learned a few things

There were a couple of connections that needed to be adjusted. We were hoping that was going to be the magic but no joy.

The engine is hard to start as you can see from the video. When it does catch it chuffs and it takes keeping the RPMs high to keep it running. We tried adjusting the idle screw in and out and adjusting the mixture -- it seemed to make no difference either way.

Arthur came over and we worked on it for a while. Reset the mixture, changed CDI's just in case, pulled the plugs and put different ones in, lots of things. Couldn't get it to run any more than the very low RPM not-all-cylinders putting. Not even as good as last night with Tim.

So I am putting everything back and tomorrow will take it to the shop. Very disappointing, but I've done all I can at this point.

Oso, have you heard any news from the shop?